When electricity is on the line

Providing electricity to a whole country is a demanding task. It gets even more demanding when roughly one-third of the country is covered with woods and the other two-thirds contain Europe’s highest summits, the Alps.

To provide undisturbed supply and keep the electricity streaming, the Alpiq EnerTrans AG integrated Leica Geosystems Unmanned Aerial Vehicle (UAV) solutions into their workflow to manage visual inspections of the powerlines, their insulators and their poles. Evolving the use of an UAV to improve workflows, Alpiq EnerTrans AG took it to the next level, creating an innovative way for vegetation management, monitoring the environment threatening aerial cables using Leica Geosystems hexacopter.

空中植被管理

Regular monitoring of the environment around infrastructural constructions is the first step in vegetation management. These structures include:

• Powerlines
• Pipelines
• Railways

下一步是计划和执行maintenance work to prevent any incidents. Therefore, a minimum distance between the surrounding flora and the lines is necessary. This is majorly important when it comes to aerial powerlines. As an insulating layer would be too heavy, the air around the lines works as a non-conducting protection. To prevent any short circuit, neither the lines to each other nor any vegetation should come closer than the minimum distance.

Earth faults and short circuits can cause heavy damage, fire and even lead to the teardown of a line, which could mean a power blackout for thousands of people. The minimum gap depends on the national laws, the operating voltage and a customised offset given by the company.

In the past, Alpiq EnerTrans AG was using experts to walk next to the powerlines to estimate the space between the conductions and the vegetation, to see if anything would interfere with the minimum gap. In doubt, the whole segment of the conduction had to be shut down and the crew had to climb up to get a more detailed view.

这个方法非常accurat也是如此e, mainly because it was based on appraisals, nor was it very efficient. With most of the constructions being built in difficult terrain, the inspections were very time consuming and it was a major effort for the crew to inspect the powerlines through the rough terrain. Apart from this method, Alpiq EnerTrans AG monitored its grid by using helicopters with infrared-, korona-, RGB-cameras, as well as laser scanners, to get ahead of possible threats caused by the environment

Alpiq was looking for new ways for their vegetation management and found their perfect match in an UAV based solution to:

• 提高效率
• Heighten safety
• Increase precision

使用无人机来获取与小型船员和轻型设备相结合提供的直升机的详细信息，是多功能性和颗粒状的完美结合。为了捕获有关分析相关的所有数据，Sony Alpha 7R具有全帧CMOS传感器（36.4megapixel），并将28毫米镜头安装在无人机的阳性上。

The first step in using an UAV to monitor the environment surrounding the powerlines is to prepare the flight plan. Every segment to be monitored later has to be surveyed before the flight to get a detailed view of the states and possible danger spots. This becomes important when the crew is planning the most efficient waypoint flight in the next step.

内部构建的飞行计划软件计算了无人机的最有效路线，地面采样距离（GSD）和高度，向您展示了整个操作的持续时间和路点。领先于这项任务的另一种方法，尤其是当该区域难以预测时，是在功能上的教学，在这里，无人机从飞行中保存了航路点，以便下次在这个地方记住它们。

To increase the precision, the a RTK/GNSS module can be attached and references the UAV with a scope of 1-3cm. This method is based on the technology of NovaTel and Leica Geosystems.

After the expulsion of the overhead lines, further processing of the data begins. The recorded images are georeferenced with the GPS data of the UAV’s logfile in a special software. Through the georeferenced data, an accurate 3D point cloud of the area and the environment is created.

在下一步中，添加了位置和极高的数据，并通过电线杆的GPS坐标引用模型。设置模型后，添加计算的电导，以模拟最大导体线圈下垂。

在进一步的过程中，计算出的点云是给瑞士公司Picterra GmbH。该软件确定植被和电源线之间的距离。这些点在确定最小距离的点云中标记。情况计划源自该模型，该模型显示了危害以及包裹的边界和数字，道路，路径，线条和桅杆名称。根据情况计划，可以清楚地找到危险点的坐标。

找到合适的差距

By using the Leica Geosystems UAV solution, Alpiq has now been able to accurately determine the distances between the overhead lines and the surrounding vegetation toas much as ± 30cm为了确保其路线的平稳操作。由于必须经常以不规则的间隔检查当前的路径，因此在这种情况下，无人机的全部潜力会产生，以从部分部分产生精确且可比的结果。

The entire monitoring can now be carried out by a small crew, since only one other person is required to watch HD live transmission on the screen. The cost advantage compared to a helicopter and the associated crew as well as the elaborate sensors is obvious. Another advantage of using an UAV is the possibility to generate precise data again and again in order not only to create snapshots but to generate a longitudinal section for a long-term study from the data obtained.

Leica Geosystems UAV as a floating multisensor platform also offers the possibility to use other measuring methods. So, Alpiq EnerTrans AG is extending the workflow to a multispectral camera, such as the Parrot Sequoia, to determine the Normalised Differenced Vegetation Index (NDVI) of the vegetation. This can identify regions that need to be inspected more frequently due to increased plant growth. This operation消除了对昂贵且大规模检查的需求使用直升机，可以准确预测被植被威胁的高架线的区域。

The UAV is also equipped with a LiDAR sensor to achieve even more precise results. By using a LiDAR sensor, the UAV can generate毫米精确点云从空中起作用，因此更精确地工作。

The advantages of collecting data for track management with an UAV are not only the reduction of costs and increased security. Rather, the UAV based open-line monitoring is a multiple flexible and allows selective and highly precise vegetation management. While in the case of an on-site inspection or the use of a helicopter, only momentary recordings are collected. The workflow generates data with an UAV, from which various scenarios can be simulated and analysed. This makes it possible not only to identify an actual situation but also to make detailed forecasts.

"The aerial robot from Leica Geosystems supports Alpiq EnerTrans AG optimally in the fulfillment of our demanding inspection tasks. A device for professionals by professionals!" - Rudolf Meier, chief executive of Alpiq EnerTrans AG

With the innovative approach of Alpiq EnerTrans AG to specify and modernise vegetation management through the use of Leica Geosystems UAV, the company not only works more efficiently, but it can also depend on solid data to counteract any malfunction.